So the White Russians were already the guys that scapegoated the Russian Jews and drove a lot of them into the arms of the Reds OTL. Given a White Russian victory (particularly if the forces in charge are the more authoritarian elements among them), it's not hard to imagine a hypothetical Nazi Russia cracking down on its own citizens and turning many of them against the regime.
I could also see Russian belligerence getting it into trouble with both Germany and Japan at the same time.
The worst plausible situation for TTL Russia is:
- Undergoing it's own version of the depression.
- Being less industrialised due to the absence of Stalin's brutal industrialisation policies.
- Being more fragmented internally due to cracking down on ethnic and political minorities.
- Having lost territory in Central Asia and/or Ukraine during the civil war.
- Fighting a war on multiple fronts (Against Japan certainly, but also possibly Turkey, China, states that broke away during the civil war, etc).
- Having a woefully unprepared officer corps due to the regime's unwillingness to reform (Remember, Germany could rest on the laurels of the existing Prussian officer class to get by, but an equally stubborn Russia in the same situation would have no equivalent asset). For that matter, we can imagine Kolchak purging some of the officers that were sympathetic to Republicanism or Constitutional Monarchy.
- Being far more militarily exhausted than Nazi Germany was OTL. Rather than the bloodthirsty zeal shown by Germany, I could see the Russian people displaying the tired apathy of France's or Italy's people OTL. Particularly if TTL Germany was showing itself to be merciful towards surrendering troops.
Similarly, we can imagine the following plausible strengths for TTL Germany:
- Rather than Hitler's increasing brutality towards his own people, the Luxemburgists would probably be all to eager to put an end to political violence as soon as expedient. Certainly there would be some initial nastiness after a revolution, but by the late 30's Germany would probably be far more united. Many of the physicists behind Operation Manhattan would still be living in their homeland. If the outside world was looking at Germany with suspicion following the revolution, this might have the accidental effect of creating a siege mentality that pushes further German unity.
- Once Germany was at war with a tangible external foe, this might even push some of the traditional militarist forces into the camp of the Germans. Erich von Manstein, just to name an example, may not be thrilled to fight under the banner of the revolution, but he would likely be willing to fight for a threatened fatherland.
- The German Communists would be all too willing to reform the economy and with it, modes of industrial production. The artisan industrial economy that failed Germany so horribly during World War II would be long gone by the time it mattered.
- A successful German revolution would probably have a knock-on effect sparking revolutionary activity in nearby locations. It's not impossible to imagine Germany having Spanish, Hungarian, Austrian or French allies by the time of the war with Russia. Pragmatism often trumps ideology in politics, and Germany would probably eventually adopt a policy of not deliberately causing revolutions in nearby states to avoid the ire of every other country nearby, but many countries in Europe had existing revolutionary activity that could be boosted by a nearby example of success.
And then there is the grand behemoth of factors that make this war winnable for Germany:
- The second war breaks out, every Bolshevik/Bolshevik sympathiser left in Russia would immediately start causing trouble.
If we imagine even a fragment of these factors coming to fruition, a victory of Germany over Russia becomes quite easy to imagine.